Method for dispensing liquid utilizing flow of liquid

ABSTRACT

A method for accurately and precisely aspirating and dispensing liquid from a in the nano-liter range without contacting the syringe tip to the target reservoir during dispensing. Such a method utilizes a partially collapsible syringe tip that compresses when subjected to pressurized fluid around its outer surface area to discharge a liquid at the tip of said partially collapsible syringe tip with a high velocity. Such a discharge of liquid at such a high speed allows even the smallest amount of liquid in the nano-liter range to be dispensed to a target reservoir without contacting the target reservoir.

This is a divisional application of the copending application Ser. No. 11/830,683.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The invention relates to a method for aspirating and dispensing micro-volumes of liquid without allowing the tip to come in contact with the target receptacle. This invention allows a relative small amount of liquid to be discharged from the tip of any syringe type apparatus. This discharge is accomplished by a compression of the collapsible syringe tip allowing the liquid to be ejected at a high velocity. Ultimately, the high velocity discharge allows such syringe type apparatus to be suspended over the target receptacle, eliminating contact between the syringe tip and the content of the target receptacle; preventing contaminants.

2. Description of the Related Art

During biomedical and pharmaceutical research, precise and accurate measurements of liquid are often essential to ensure proper results. When experiments are conducted in large scales such as milliliter ranges, precisions in the nano-liter range are insignificant to the outcome of the experimentation. However, as technology improves, syringes and pipettors are now capable of dispensing liquid in the nano-liter range instead of milliliter ranges. This type of precise dispensing is hard to achieve, as the capillary effect creating a convex liquid tip prevents a small amount of liquid to be aspirated from the syringe with any sort of accuracy. The capillary effect is generated by the surface tension between the inner surface of the syringe tip and the liquid; consequently, such surface tension prevents a small amount of liquid to be accurately dispensed from the syringe tip.

In order to address the capillary effect discussed above, nano-liter syringe tips often immerse themselves in the target receptacle already filled with fluid to properly dispense the correct amount of liquid. However, as it is blatantly obvious, such attempts to address the undesirable capillary effect within a syringe tip create a new problem of undesirable contaminants. Contaminants occur when residual amount of liquid from previous samples to be introduced are left in the target receptacles. Although contaminants in small amounts do not generally affect the desired results in large scale experimentations in the milliliter range, these small contaminants are devastating in nano-liter experimentations.

Capillary based systems have been used to address this issue of nano-liter dispensing by impinging the tip of the syringe into the floor of the target reservoir. When the tip of the syringe comes in contact with another surface, the surface tension along the internal walls of the syringe tip is released, causing even nano-liter amount of liquid to be dispensed from a syringe tip. These capillary based systems although effective in addressing the precision dispensing issue, is completely ineffective in creating a non-contact method of aspiration that is required in addressing the contaminant issue.

Currently in the art, there are no apparatus that is capable of addressing this issue of nano-liter dispensing without contacting the syringe tip with the target reservoir.

Due to the foregoing, it can be seen that there is a need in the art for a method of dispensing liquid in the nano-liter range without allowing the tip of the syringe to come in contact with the target reservoir. Moreover, it will be desirable to be able to achieve this on multiple syringes at once, as experimentation of chemical reactions often requires multiple samples.

Consequently, it will be an advance in the art to provide a method to utilize a compressed fluid source to collapse a syringe tip that is partially compressible allowing the air that is within the internal walls of the compressible portion to push out any liquid that is held in the bottom tip of syringe. Moreover, such an innovation will allow for an effective, efficient, and contaminant free way of allowing nano-liter dispensing of liquid from a syringe.

SUMMARY OF THE INVENTION

To minimize the limitations found in the prior art, and to minimize other limitations that will be apparent upon the reading of the specifications, the present invention provides a method to dispense a nano-liter amount of liquid from a syringe tip or any tip without making contact with the target receptacle. This is accomplished through a partially collapsible syringe tip that collapses when subjected to a high pressure of fluid, thus overcoming the surface tension holding the fluid in place; ejecting the liquid out of the syringe at a high speed without coming in contact with the target receptacle.

A method in accordance with the present invention for dispensing a liquid comprises: enclosing a portion of a partially collapsible syringe tip in a fluid chamber; opening a set of valves juxtaposed at both sides of said fluid chamber controlling a flow of fluid into said fluid chamber; and allowing said flow of fluid into said fluid chamber; wherein said flow of fluid exerts a force on said partially collapsible syringe tip to dispense said liquid.

It is an objective of the present invention to dispense nano-liter amount of liquid from a syringe tip without contaminating the target receptacle.

It is another objective of the present invention to dispense a liquid in a non-contact fashion.

It is yet another objective of the present invention to dispense nano-liter amount of liquid from a syringe tip without contaminating the target receptacle in a simple inexpensive manner.

It is yet another objective of the present invention to achieve high speed dispensing of the liquid.

It is yet another objective of the present invention to be able to control precise aspiration volume within the syringe tip.

It is yet another objective of the present invention to dispense liquid from multiple syringes simultaneously.

It is yet another objective of the present invention to dispense the same amount of precise liquid from multiple syringes simultaneously.

It is yet another objective of the present invention to dispense nano-liter liquid without any fine control of the compressed fluid flow.

It is yet another objective of the present invention to utilize compressed fluid to collapse a collapsible portion of the syringe tip to eject liquid out of the syringe tip. 

1-9. (canceled)
 10. A method of dispensing a liquid comprising: enclosing a portion of a partially collapsible syringe tip in a fluid chamber; opening a set of valves juxtaposed at both sides of said fluid chamber controlling a flow of fluid into said fluid tight chamber; allowing said flow of fluid into said fluid chamber; wherein said flow of fluid exerts a force on said partially collapsible syringe tip to dispense said liquid.
 11. The method of claim 10, wherein said partially collapsible syringe tip is further comprising: a first rigid portion at a proximal end of said partially collapsible syringe tip; a second rigid portion at a distal end of said partially collapsible syringe tip to dispense said liquid; and a collapsible portion connectively placed between said first rigid portion and said second rigid portion adapted to be enclosed by said fluid chamber.
 12. The method of claim 11, wherein said fluid chamber encloses said collapsible portion of said partially collapsible syringe tip.
 13. The method of claim 12, wherein said fluid chamber is capable of enclosing a plurality of partially collapsible syringe tips.
 14. The method of claim 13, further comprising: connecting a plurality of fluid chambers to said valves to create a plurality of fluid chambers. 15-19. (canceled) 